Exporting which partitions to md-configure

H. Peter Anvin
2006-01-31T00:52:27Z

I'm putting the final touches on kinit, which is the user-space
replacement (based on klibc) for the whole in-kernel root-mount complex.
Pretty much the one thing remaining -- other than lots of testing --
is to handle automatically mounted md devices. In order to do that,
without adding userspace versions of all the paritition code (which may
be a future change, but a pretty big one) it would be good if the
partition flag to auto-configure RAID was available in userspace,
presumably through sysfs.

Any feeling how best to do that? My current thinking is to export a
"flags" entry in addition to the current ones, presumably based on
"struct parsed_partitions->parts[].flags" (fs/partitions/check.h), which
seems to be what causes md_autodetect_dev() to be called.

Note that this should be available even if md isn't compiled into the
kernel, thus making it possible to load md as a module before running
kinit, or to make the equivalent of the kernel mounting sequence from a
totally runtime user tool.

-hpa